This is intended to be an information thread to better everyone's understanding of performance testing on wheels... so that we won't be buying wheels just based on looks

I am by no means a wheel expert, so this will be a working document, and I will add more information as people reply to this thread.

Performance Standards/Specifications
From what I've read there are several major performance specifications for wheels from:

SAE (Society of Automotive Engineers)

TÜV (German regulatory agency)

ISO (International Standards Organization)

JWL (Japan Light Alloy Wheel Standard, VIA conducts the tests)

Are Performance Tests Mandatory?
It depends on where you live. In Japan for example, all alloy wheels for passenger cars (with 3, 5, and 7-number plates) to receive JWL/VIA approval to be legal for sale. In the U.S. however, there are only dimensional requirements per D.O.T. but no performance requirements.

What's Involved in These Tests?
I have to be honest here, so far I've only scanned through the JWL/VIA and SAE J2530. So experts please chime in

All these tests are based on the specific load rating of the wheel. For example, a wheel rated at 690 kg will be applied a load derived from 690 kg.

A higher rated wheel will be applied a higher load during the tests, and hence more durable. But of course when the load rating is unnecessarily high, the wheel may become too heavy. Below are the key tests that are performed:

Dynamic Cornering Fatigue Test - This is a test that simulates the forces/moments put on a wheel when the vehicle is turning a corner or going around a curve. For JWL, a bending moment (based on load rating, load radius, offset, etc.) is applied for at least 100,000 revolutions.

One interesting note here is JWL requires a higher safety factor (e.g. more load) for cast wheels (2.0) vs. forged (1.5). I guess this is why a properly designed cast wheel can be just as strong/durable as a forged wheel... but of course the cast may be heavier due to more material used.

Dynamic Radial Fatigue Test - The main purpose of this test is to check the durability of the wheel disc. This is a test that simulates the forces that the wheel experiences with a tire mounted and carrying the weight of the vehicle, passengers and/or cargo.

Here for JWL a radial force 2.25x the load rating is applied for over 500,000 revolutions!

Impact Test - This is a test designed to test the effect on the wheel in the event of an impact to the wheel such as hitting a pot hole or side impact into a curb. This test mainly checks for tire air retention and confirms the strength of the structure joining the rim and disc. The test basically involves the dropping of a weight at various locations on a wheel.

What Constitutes Pass or Fail?
Generally a wheel should not fail at the end of these tests, i.e. present cracks, be significantly deformed, or lose air pressure.

However, the actual passing criteria varies depending on the standard and test used. For example, JWL for trucks do not allow any deformation, while as JWL for cars only need to be able to hold air after the tests.

Recently I came across a page on Rays Wheels. Below is a figure illustrating how Rays developed their own standards (JWL+R) on top of JWL.

For example, fatigue testing cycles have been drastically increased. And in addition to the JWL-standard 13 deg. impact test, JWL+R drops a 2200lb weight at a 90 deg. angle from ~5.5". And then the same wheel is used for an additional near 1 million cycles of radial endurance testing

Great info. Ray's JWL+R mimics what most JDM OEMs do already as a minimum. Impressive for an aftermarket wheel company to pony up and do the extended testing. This is a good example on how OEM requirements compare to aftermarket.

In another thread Lon@HRE explained TUV certification in detail and HRE's compliance. Lon's explanation follows. Thanks to Lon for this great information.

Quote:

Originally Posted by Lon@HRE

What is TUV?

Over the years HRE has received numerous questions regarding TUV certification. What is it? Why is it important? What is required? Other companies are starting to claim they have TUV certification and we have received numerous questions as to whether these claims are true or false. HRE can’t determine whether others are properly going through the legitimate process of getting TUV approval or just falsely claiming TUV approval to improve their image. What we can do is clarify what is required of TUV and what you should be looking for from a company that claims to have TUV approval.

1) WHAT IS TUV? - In the case of wheels, TUV is a European auditing and certification body that ensures wheels manufactured for sale in Germany, Switzerland and Austria meet international (ECE Regulations), EC (European Community) directives, and German Motor Traffic Agency (KBA) road traffic legislation.

2) HOW DOES TUV WORK? - There are 3 major aspects to receiving TUV certification.
a) Manufacturer Certification (Certification of the wheel manufacturer’s quality management system) - If you aren’t an actual manufacturer you can’t be a TUV certified manufacturer. If you’re not a real manufacturer and your supplier isn’t a TUV certified manufacturer you cannot have your wheels TUV approved. This requires that the actual manufacturing facility (in HRE’s case this is our production facility at our headquarters in Vista, CA) passes an audit every 3 years by TUV authorities from Europe. The facility must ensure the manufacture of its wheels meet the standards set by the authorities above in point 1. This is very similar to an ISO 9001 audit and designed to ensure consistent quality of manufacture. TUV wants to ensure that wheels sent to TUV for te sting are not “ringers” and that all wheels manufactured at the approved facility meet the same standards. HRE’s quality management system was originally certified in 2008 by Germany and recertified in 2011 by Austria (which is applicable for Germany).

b) WHEEL TESTING CERTIFICATES (Certification of wheels as conforming to geometric standards and having passed structural fatigue and impact requirements for specific vehicle and load rating requirements) - Once a manufacturer’s facility is certified they are then able to send wheels to Europe to pass TUV geometric tolerance analysis and testing for fatigue and impact. This is not a generic style-based test, but vehicle-based with each style being tested with the proper widths and offsets and load rating for the appropriate vehicle targets. This is a very time consuming and costly endeavor for any manufacturer to TUV certify their entire wheel offering, particularly a brand like HRE that makes custom fitments and offers dozens of styles for any particular vehicle. Given this fact, HRE does not certify every style and fitment, however we do have multiple styles in several fitments tested, approved and certified for sale in Germany, Switzerland and Austria. Regardless of certification, ALL HRE wheels are designed to pass TUV structural specifications (with varying load ratings depending on vehicle targets) and are sent for certification when the demand for them in Europe meets a minimum threshold.

c) VEHICLE OWNER CERTIFICATION (Certificates ensuring wheels installed on an owner’s vehicle are TUV certified for that vehicle) - This is a certificate that the owner of the vehicle receives from TUV authorities showing his wheels are TUV certified so he can legally register his vehicle and pass annual inspections in Germany. The wheel manufacturer does not supply this document.

3) IS TUV FOR WHEELS ONLY? - TUV does not only cover wheels. It covers everything from toys to wheels to appliances so companies may hold TUV certificates that do not in any way allow them to legally sell wheels in Germany, Switzerland or Austria. By the same token HRE is only able to sell wheels (not toys) and only those wheels tested in Europe having passed the appropriate tests. None of this is possible without FIRST receiving the manufacturer certification. More importantly, simply by having a wheel pass a TUV test does NOT mean you are a TUV certified manufacturer. You must have a manufacturing facility to certify and that facility must pass the audit.

4) WHY DOESN'T HRE PUBLISH TUV CERTIFICATIONS? - We’ve been asked for a long time to publish TUV certificates. For many reasons HRE does not publish internal specifications and documents, but we will deviate from that decision to help clarify the confusion and show you our manufacturer certificates from 2008 and 2011 and we will show you an example of a wheel testing certificate; in this case the latest wheels sent to TUV for testing, a P43 in 20x9.5 ET42, PCD 5/114.3. The tests required 3 wheels to be tested for cornering fatigue, radial fatigue and impact at 750kg, a much higher level than the original design load rating. All passed. These tests certify the P43 style in that specific width, offset and PCD for that specific load rating.

5) HOW DO I KNOW IF A COMPANY IS REALLY TUV APPROVED? - TUV obviously wants to ensure others aren’t making false claims about TUV approval. For this reason they have a simple website system to check a manufacturer’s TUV Registration ID number. HRE’s current TUV ID number is 20102112006509. This number can be confirmed as genuine by following the link below to the TUV website and entering the registration number or simply typing in HRE. Ask a manufacturer for their registration ID number and website link. They should be proud to give it to you.